Friction clutch



arch 18 1924 1,487,010 J. BOHLI I FRICTION CLUTCH Filed Dec. 22 1922 :r'aoem mom, or soto'rnu I a or someone, SWITZERLAND.

a" swmnnnann, nssremion 'ro 17min sorm'mna,

rmc'rron'onuron.

Application filed'llec'ember 2a, was. Serial mi. 0083551.

To all whom it may concern:

, Be it known that I, Jaoouns Born-a, a

citizen of the'Swiss Republic, residing at 304, Obach, Solothurn, Switzerland; have ina vented certain new and useful Improvements in Friction Clutches, of which the followingisa specification.

This invention has 'for its object to rovide an. improved friction clutch for sort in periods .of working. This improved friction clutch "has the, advantage of being safer and.

more reliable in working than other clutches of this type.

The frlction' clutches usually employed, such as the cone clutch, the steel lamination clutch, etc... all have the drawback that even the slightestquan'tity of oil penetrating into the same has an injurious efiect upon their action.

In some cases it is however not possible to rotcct those known clutches permanently rom the penetration of lubricating oil. In the steel lamination clutch the injurious influence of the oil consists mainly in rendering the lamellae very liable to adhere to ether, so that it is often not possible to efect a pro er unclutching, whereas both in the steel amination clutch and the cone clutch the friction is greatly reduced by oil so that a much greater axial pressure has to be exerted for the purpose of transmitting the desired power through those types of clutches. As a matter of fact it has been found that the footstep bearing or thrust bearings of such clutches are deteriorated by the high axial pressure. a

An improved clutch according to the present invention is free from those drawbacks. An essential feature of its construction conan extent as will cause jamming of; the balls,

whereupon the two rin together with the parts, combined with t ose rings and comined with one another, are carried along by the drivin shaft owing to the friction generated by t e exerted axial pressure.

- in which.:

sists in a normal roller or ball.-.'bearing Aeonstructionaliexample of an improved 5 friction clutch according to this invention is illustrated in the accompanying drawings Figure 1 is a 10m itudinal section of the%. improved clutch lIlJtS open condition.

. igure 2 is a lon itudina] section of the said-clutch in'the c .osed condition.

Figure 3 is-a front view of the ball-drivin%member hereinafter described. 1 igure 4: is a side view-thereof. I In the illustrated embodiment of this invention, the ball-driving member 7) has the form of a ball cage fixed on the driving shaft a. This ball cage 72 is made in one piece having the shape of a disc provided on one side with axially longitudinal projections 0 arranged at equal distances apart with their lateral boundary surfaces contoured to the sha e of the balls is. j

T e member b may be made for instance 75 by forming the disc at first with an annular mm on one side, into which apertures of a size correspondin to the diameter of the balls are then drl led axially at' equal dis-" 7 tances apart. In these apertures the balls k are located loose, and in the open condition of the clutch theytouch lightly the inner and outer ball-bearing rings- The o uter ballbearing ring (1 is pressed immovably into the driven clutch element e, whereas the in-. ner ball-bearing ring f'is fixed on a loose piece 9 which has the shape of a disc pro-- vided on one side with a circular central neck for the reception of the inner ball-bearing ring 7. This-disc g is formed on its periphery with a projection s which en ages 1n a longitudinal slot t in-the driven c utch element e in such a manner-that both parts must hold together and must revolve positively with one another, while remaining longitudinally adjustable relatively to each other in the direction parallel to t eir common axis of rotation.

The carrier 9 of the inner ball-bearing ring is. held in its central position both by means of its peripheryv fitted into the cylindrical aperture of the driven clutch element e and by being centered by the balls themselves. a

The driven clutch element e is readily adjustable to and fro in the axial direction. It is mounted on the outer surface of the fixed bearing body h, and also on a cylindrical i any side.

' ly in the direction 0 shoulder on the inner side-of thecover z of the, bearing casing. The axial pressure is taken by a screw Z. l

The operation of the improved clutch is as follo s:--

In its open condition (shown in Figure 1) the balls It are quite free because they are not acted upon by any pressure from By overcoming a very small frictional resistance they are carried round positively by the driving shaft a by means of the driverb which is constructed in the form of a ball cage; the two parts 6 and 9, together with the rings (1 and 7, remaining stationary;

When the clutch is to be closed (Fig; 2)

pressure must be exerted upon the part cin order that the said art shall move axial.- f the arrow- (Fig. 1). In this manner the balls is are jammed between the rings (1 and f which are shaped on their inner surfaces to conform with the curvature of said balls, and these rings as well as the parts 9 and e that engage sald rin and also engage one another, are carried round' by the driving shaft a. The power of the driving shaft a can then be transmitted for instance by means of teeth it formed on the part e, to any desired further point. x

The pressure serving to produce the couplin together of the driving and driven clutc elements may also be exerted upon the clutch element e, electro-magnetically. For this purpose an annular magnetic coil m is arranged round the shaft a. By the magnetic excitation of this coil a flange 0 carrying pins n is attracted The pins n extend through'the shaft bearin body and press against the loose disc 12 w 'ch in its turn exerts upon the driven clutch element e the pressure required for closing the clutch.

What I claim is 1. In a friction clutch for short periods of working, the combination with a rotai'v driving shaft, of' a rotary driving clutc element connected thereto, an axially slidable rotary driven clutch element, an axially slidable rotary ball bearing ring, a non-- slidable rotary ball bearing ring, balls located between said two ball-bearing rings, and positive driving means for carrying said balls round idly so long as the clutch is open, whereas .by applying axially directed pressure to said axially slidable clutch element, said axially slidable ballbearing ring will be caused to slide and jam said balls against said non-slidable ball bearing ring, whereby said two rings and said balls and said driven clutch element will be carried" round by the driving shaft, thus closin the clutch.

'2. In a riction clutch for short periods of working, thecombination with a rotary driving shaft, of a rotary drivin clutch element connected thereto, an axiadly slidable rotary driven clutch element, an axially slidable rotary ball-bearing ring connected to said driven clutch element, a non-slidable rotary ball-bearing ring, also connected to said driven clutch element, balls located between said two ball-bearing rings, and a driving member fixed on the driving shaft, for engaging said balls and driving them round positively while the clutch is open and also while, the clutch is closed the connection between said two rings and said driven clutch element being such that said two rings are independent of each other as regar s axial motion, while being capable of rotating together. c

3. In a friction clutch for short periods of working, the combination. with a rotary driving shaft, of a rotary driving clutch element connected. thereto, an axially slidable rotary driven clutch element, an axially slidable rotary ball-bearing ring, a nonslidable rotary ball-bearing ring, balls located between said two ball-bearing rings, positive driving means for carrying "said balls round when the clutch is open and also when the clutch is closed, and an electro-magnetic device for causing, said axially slidable driven clutch element to slide axially and cause said axially slidable ball loearing rin to slide and thus jam said balls against sai non-slidable ball-bearing ring and thereby close the clutch.

in testimony whereof I have signed my name to this specification.

JACQUES BUHLI.

MIL 

